Extendable arm punching apparatus

ABSTRACT

A punching apparatus is provided with a tool holder that has integral upper and lower arms. The upper and lower arms are provided with punches and dies, respectively. In one form, a smaller punch and die set is spaced longitudinally behind a larger punch and die set and laterally offset in a direction toward the work sheet clamps. In another form, the smaller punch and die set is spaced longitudinally forward in a direction toward the work sheet clamps and laterally offset from the larger punch and die set. The tool holder is extendable longitudinally and laterally to accurately align either the large punch and die set or the smaller punch and die set beneath a striker. In one form, the upper arm is recessed closely adjacent the smaller punch to reduce interference with the work sheet clamps. In both forms, the tool holder can also be extended further to a tool changing position.

" United States Patent [191 Daniels [451 July 22, 1975 EXTENDABLE ARM PUNCHING APPARATUS [75] Inventor: Dennis Daniels, Bellevue, Wash.

[73] Assignee: U.S. Amada, Ltd., Seattle, Wash.

22 Filed: June 5, 1974 [21] Appl. No.: 476,375

Related U.S. Application Data [63] Continuation-impart of Ser. No. 445,487, Feb. 25,

I974, abandoned.

[52] U.S. Cl. 83/409; 83/549; 83/551 [51] Int. Cl B26f l/04 [58] Field of Search 83/409, 549, 550, 551, 83/552 [56] References Cited UNITED STATES PATENTS ll7,593 8/1871 Barney 83/549 X Primary Examiner.lames M. Meister Attorney, Agent, or Firm-Seed, Berry, Vernon & Baynham [57] ABSTRACT A punching apparatus is provided with a tool holder that has integral upper and lower arms. The upper and lower arms are provided with punches and dies, respectively. In one form, a smaller punch and die set is spaced longitudinally behind a larger punch and die set and laterally offset in a direction toward the work sheet clamps. In another form, the smaller punch and die set is spaced longitudinally forward in a direction toward the work sheet clamps and laterally offset from the larger punch and die set. The tool holder is extendable longitudinally and laterally to accurately align either the large punch and die set or the smaller punch and die set beneath a striker. In one form, the upper arm is recessed closely adjacent the smaller punch to reduce interference with the work sheet clamps. In both forms, the tool holder can also be extended further to a tool changing position.

8 Claims, 10 Drawing Figures SHEET PATENTEB JUL 2 2 I975 m QE PM? A SHEET PATENTEDJUL22 ms JFJIGOQ FIGO 11 0) EXTENDABLE ARM PUNCI-IING APPARATUS This application is a continuation-in-part of application Ser. No. 445,487, filed Feb. 25, 1974, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains to punch presses of the type having the punch and die held in the upper and lower arms, respectively, of a tool holder. It is particularly applicable to punch presses of the type having a duplicator.

2. Description of the Prior Art Punching apparatuses of the type employing a tool holder which carries a punch and die in integral upper and lower arms, respectively, have heretofore carried but a single punch and die set which, through adaptors, can accommodate a range of punches and dies varying, for example, from 1 A to 3 /2 inches in diameter for a large set, and H32 to l A inches in diameter for a small set. The holder can carry only one of these set ranges; and to accommodate the second set range, the tool holder is removed from the punching apparatus and replaced with a tool holder having a die set to accommodate the other range. Large tool holders are quite heavy and require two workmen to replace them, which is time-consuming and costly.

SUMMARY OF THE INVENTION It is an object of this invention to provide a punching apparatus of the type described in which the tool holder can accommodate two size ranges of punches and dies without being replaced.

It is another object of this invention to provide a punching apparatus of the type described which is less expensive to manufacture and more efficient to use.

Basically, these objects are accomplished by providing, in a punching apparatus of the type having a tool holder with upper and lower arms, large and small punch and die sets. The smaller set is longitudinally spaced from the larger punch and die set and offset laterally from the larger punch and die set. In each form, an offset of the smaller punch and die set is in the direction towards the work sheet holding clamps. Preferably, the tool holder can be extended longitudinally and laterally to shift the center of the large punch and die set out from beneath the striker and to position the smaller punch and die set beneath the striker. Preferably, a second, further extended position is provided so that the punches and dies in each set can be changed to vary the punch and die sizes within the respective ranges of the large and small sets.

As is apparent, tool changing is greatly simplified since it is no longer necessary to physically remove the tool holder from the punching apparatus. It is estimated that a tool change in the larger size range of punch and die sets takes only about 30 to 40 seconds, and within the smaller range, only about seconds. Since only one tool holder is used, the initial expense in manufacturing the machine is lessened. By providing both the large set and the small set in the tool holder, most of the commonly used punch and die sets can be used. By providing the lateral or longitudinal offset of the smaller die in the direction of the work sheet clamps, interference with the horizontal movement of the workpiece clamps is reduced, thus allowing the work sheet clamps to operate closely to the small punch and maximizing the punchable area of the work sheet.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective of one form of a punching apparatus employing the principles of the invention.

FIG. 2 is a vertical section taken along line 2-2 of FIG. 3.

FIG. 3 is a fragmentary horizontal section taken along line 33 of FIG. 1.

FIGS. 4-6 are operational schematic illustrations showing the three positions of the tool holder of FIG. 1. FIG. 4 is a fully retracted position, FIG. 5 shows a longitudinally and laterally extended position, and FIG. 6 illustrates a further extended position for tool chang- FIG. 7 is a fragmentary vertical section taken along line 7 7 of FIG. 3.

FIG. 8 is a fragmentary vertical section taken along line 88 of FIG. 5.

FIG. 9 is a fragmentary isometric of a second form of tool holder. I

FIG. 10 is a schematic, fragmentary, operational plan of the embodiment'of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As best shown in FIG. 1, punching apparatus 10 is provided with a work-supporting table 12 and a conventional duplicator mechanism 14. As is well understood, the duplicator has a probe 16 that can be inserted in a pattern of holes in a templet T, with a pair of work sheet holding clamps l8 gripping a work sheet W and positioning the work sheet in the same pattern as the pattern of holes in the templet. This type of equipment is conventional and well known in the art. It should be understood that the principles of the invention are not limited to duplicator-type punch presses.

The punching apparatus also has a conventional ram frame 20 which is provided with a striker 22 (FIG. 2). A tool holder 24 is slidably mounted for movement along its longitudinal and transverse axes between three different positions. The tool holder is of the type commonly referred to as a swan neckand includes integrally connected upper and lower arms 26 and 27, respectively. The tool holder in this invention carries a large punch and die set 30 and a smaller punch and die set 32. It should be understood that the term die set, as used in this application, is intended to refer to a range of punches and dies generally considered usable for a large set and a small set. For example, punch and die set 30 would normally be expected to hold a range of punches and dies of between I inch and 3 /2 inches. Punch and die set 32 would be expected to hold a range of punches and dies varying from 1/32 inch to l A inch. Obviously, however, a single large punch and die and a single small punch and die could still be employed to utilize the principles of the invention.

For the purpose of brevity, only a single large punch and die and only a single smaller punch and die will be referred to herein after. The large punch and die set includes a conventional punch 33 and a conventional die 34. The smaller punch and die set 32 includes a punch 35 and a die 36.

For the purpose of extending and retracting the tool holder 24, the punching apparatus is provided with a primary cylinder 38 pivoted to the table 12 and having a piston rod 39 that is pivotally connected to a slider 40. Slider 40 rides in a guide track 40a and is pivotally connected to a second slider 41 which rides in a guide track 41a on the lower arm 27. Slider 41a is pivotally connected to the piston rod 60. Thus, movement of the piston rod 39 will retract and extend the tool holder. Retraction of the tool holder is limited by an adjustable stop 42 to accurately position longitudinally the center of the punch and die set 30 beneath the striker axis indicated by the axis marks 44.

Lateral location of the tool holder in the fully retracted position is determined by an adjustable stop 46. Retraction of the piston rod 39 moves the tool holder longitudinally outwardly and laterally simultaneously. The extent of longitudinal movement is determined by an adjustable stop 48. Lateral movement is determined by a guide mechanism including a cam roller 50 and a sloped track 52. Extension of the tool holder thus moves the cam surface 52 against the roller 50, shifting the tool holder laterally into the position shown in FIG. 5. Exact location of the punch and die set 32 can then be preset by the adjustments 48 and 54. In this position, the smaller punch and die set 32 is thus aligned with the striker axis 44.

Further extension of the tool holder is provided by a secondary cylinder 58 that is pivotally mounted to the lower arm 27. The cylinder is provided with a piston rod 60 that is pivotally connected to the bracket slider 41. Consequently, extension of the piston rod 60 will move the tool holder further longitudinally into the position shown in FIG. 6. In this position, the punch and die sets 30 and 32 are free from the worktable and striker, and the tools can readily be replaced.

A spring 62 maintains the tool holder biased toward the cam roller 50 to maintain accurate alignment of the tool holder.

In the overall operation of the device of FIGS. 1-8, the operator punches one of three control buttons 70 to energize the cylinders 38 or 58. Assuming a hole is first to be punched with the large punch and die set 30, the piston rod 39 will be extended and the piston rod 60 retracted, as best shown in FIG. 4. Assume next that several small holes will be punched using the punch and die set 32. The operator will push another of the buttons 70, which will cause piston rod 39 to be retracted, bringing the tool holder into the position shown in FIG. 5. An important feature of the invention is that the lateral displacement of the tool holder for using the smaller punch and die set 32 allows the workpiece clamps 18 to approach very closely to the punch 35, thus minimizing the area on the work sheet that cannot otherwise be punched. To even further reduce interference, the upper arm is provided with a forward portion 74 that has a peripheral edge that is recessed as at 76. Thus the workpiece clamp approaching the smaller punch 35 from the rear can move close to the punch.

To change the tools, the operator pushes another of the buttons 70, which extends the piston rod 60 to extend the tool holder.

The embodiment of FIGS. 9 and is in concept basically the same as that of the embodiment of FIGS. 1-8. A swan neck tool holder 80 is slidably mounted on a guide block 82 that is pivotally mounted in a slidable pivot block 83. The tool holder is reciprocated longitudinally along the guide block by a cylinder and piston 38. An adjustable stop rod 84 extends through the guide block and accurately limits the retracted motion of the tool holder to position the smaller punch and die set 32 beneath the striker axis 44. A second adjustable stop 86 is connected to the tool holder and engages the guide block 82 when the tool holder is extended to position the larger punch and die set 30 beneath the striker axis. Lateral l'IIO'v'-Z,I".1iOf tin he? is provided by a cylinder and piston 88. Accurate location of the punch and die sets beneath the striker axis is provided by adjustable stops 89 and 90.

Movement of the tool holder into a further extended tool changing position is provided by a third cylinder and piston 92 that reciprocates the pivot block 83 which holds the pivot pin for the guide block 82. Extension of the piston rod of cylinder and piston 92 will move the guide block and tool holder longitudinally to clear the table 12 for tool changes. Retraction of the pivot block 94 against an adjustable stop 98 will accurately position the pivot block and thus the tool holder for additional punch and die positioning by the cylinder and pistons 38 and 88.

The basic difference between the embodiments of FIGS. 1-8 and 910 is in the position of the work sheet clamps 18. In the first embodiment, the clamps are on the side of the tool holder; whereas, in the latter embodiment, the clamps are in front of the tool holder. Since the smaller punch and die set of FIGS. 9 and 10 is spaced forward of the larger punch and die set, in the direction toward the clamps 18, minimum interference with the clamps is achieved in much the same manner as with the first embodiment. That is, in both embodiments, the edge of the larger punch and die set does not unduly restrict movement of the work sheet clamps when punching smaller holes since the smaller punch and die sets are offset in the direction of the clamps.

While the preferred embodiments of the invention have been illustrated and described, it should be understood that variations will be apparent to one skilled in the art. The invention is not to be limited to the specific embodiment illustrated.

The embodiments of the invention in which a particular property or privilege is claimed are defined as follows:

1. In a punching apparatus of the type having a work sheet supporting table, work sheet clamps for holding a work sheet on the table, means for moving the work sheet clamps over the table, and a tool holder having an upper arm provided with a punch and a lower arm provided with a die and movable for positioning said punch and die beneath a striker, the improvement comprising: a second smaller punch and die spaced from said first punch and die on said upper and lower arms in the direction toward said work sheet clamps, and

means for moving said tool holder longitudinally and laterally for positioning said second punch and die beneath said striker whereby a plurality of tools may be employed to punch said work sheet.

2. The punching apparatus of claim 1, said second punch and die being longitudinally offset from said first punch and die and laterally offset from said first punch and die in a direction toward said work sheet clamps, said tool holder moving means including guiding means for positioning said tool holder laterally so as to locate said laterally offset second punch and die accurately beneath said striker.

3. The punching apparatus of claim 2, said tool holder moving means including primary moving means for moving the tool holder between a fully retracted position with the first punch and die beneath said striker to a partially extended position with the second punch and die beneath the striker, and

secondary moving means for further extending the tool holder to a tool changing position.

4. The punching apparatus of claim 3, said primary moving means including adjustable stop means and spring means for holding the tool holder against said guiding means and said guiding means for said tool holder moving means being adjustable for accurately locating the punches and dies beneath said striker.

5. The punching apparatus of claim 3, said primary and secondary tool holder moving means being recessed below said work sheet supporting surface for allowing free passage of said work sheet.

6. The punching apparatus of claim 2, said upper arm having a forward portion provided with a peripheral edge closely adjacent said first and second dies and recessed inwardly around said second die to allow movement of the work sheet clamps close to said second die.

7. The punching apparatus of claim 4, said upper arm having a forward portion provided with a peripheral edge closely adjacent said first and second dies and recessed inwardly around said second die to allow movement of the work sheet clamps close to said second die.

8. The punching apparatus of claim 1, said second punch and die being laterally offset from said first punch and die and longitudinally offset in a direction toward the work sheet clamps. 

1. In a punching apparatus of the type having a work sheet supporting table, work sheet clamps for holding a work sheet on the table, means for moving the work sheet clamps over the table, and a tool holder having an upper arm provided with a punch and a lower arm provided with a die and movable for positioning said punch and die beneath a striker, the improvement comprising: a second smaller punch and die spaced from said first punch and die on said upper and lower arms in the direction toward said work sheet clamps, and means for moving said tool holder longitudinally and laterally for positioning said second punch and die beneath said striker whereby a plurality of tools may be employed to punch said work sheet.
 2. The punching apparatus of claim 1, said second punch and die being longitudinally offset from said first punch and die and laterally offset from said first punch and die in a direction toward said work sheet clamps, said tool holder moving means including guiding means for positioning said tool holder laterally so as to locate said laterally offset second punch and die accurately beneath said striker.
 3. The punching apparatus of claim 2, said tool holder moving means including primary moving means for moving the tool holder between a fully retracted position with the first punch and die beneath said striker to a partially extended position with the second punch and die beneath the striker, and secondary moving means for further extending the tool holder to a tool changing position.
 4. The punching apparatus of claim 3, said primary moving means including adjustable stop means and spring means for holding the tool holder against said guiding means and said guiding means for said tool holder moving means being adjustable for accurately locating the punches and dies beneath said striker.
 5. The punching apparatus of claim 3, said primary and secondary tool holder moving means being recessed below said work sheet supporting surface for allowing free passage of said work sheet.
 6. The punching apparatus of claim 2, said upper arm having a forward portion provided with a peripheral edge closely adjacent said first and second dies and recessed inwardly around said second die to allow movement of the work sheet clamps close to said second die.
 7. The punching apparatus of claim 4, said upper arm having a forward portion provided with a peripheral edge closely adjacent said first aNd second dies and recessed inwardly around said second die to allow movement of the work sheet clamps close to said second die.
 8. The punching apparatus of claim 1, said second punch and die being laterally offset from said first punch and die and longitudinally offset in a direction toward the work sheet clamps. 